Fast identification of crystalline orientation of anisotropic two-dimensional materials using scanning polarization modulation microscopy

In this work, we have demonstrated that scanning polarization modulation microscopy (SPMM) provides a fast method for the identification of crystalline orientation of anisotropic two-dimensional (2D) materials. Using home-built 532 nm excited transmission SPMM, we identified the crystalline orientation of 2D orthorhombic black phosphorus, monoclinal 1T′-MoTe₂, and triclinic ReS₂ by measuring signals in only two incident polarization directions. So, it took just a few seconds to identify the crystalline orientation of anisotropic 2D materials. Our studies revealed that the SPMM method could be applied to arbitrary anisotropic 2D materials when selecting a suitable wavelength.